Rapid conductive cooling using a secondary process plane

ABSTRACT

A method and apparatus for thermally processing a substrate is provided. In one embodiment, a method for thermally treating a substrate is provided. The method includes transferring a substrate at a first temperature to a substrate support in a chamber, the chamber having a heating source and a cooling source disposed in opposing portions of the chamber, heating the substrate to a second temperature during a first time period while the substrate is disposed on the substrate support, heating the substrate to a third temperature during a second time period while the substrate is disposed on the substrate support, and cooling the substrate in the chamber to a fourth temperature that is substantially equal to the second temperature during the second time period.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/887,407 (Attorney Docket 011312/USAC01), filed Sep. 21, 2010, whichis a continuation of U.S. patent application Ser. No. 11/925,600(Attorney Docket 011312/USAD01), filed Oct. 26, 2007, which issued asU.S. Pat. No. 7,812,286 on Oct. 12, 2010, which is a divisional of U.S.patent application Ser. No. 11/611,061 (Attorney Docket 011312/USA),filed Dec. 14, 2006, which issued as U.S. Pat. No. 7,378,618 on May 27,2008. Each of the aforementioned patent applications is incorporatedherein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

Embodiments of the present invention generally relate to a method andapparatus for processing semiconductor substrates. More specifically, toa method and apparatus for thermally treating semiconductor substrates.

2. Description of the Related Art

Integrated circuits have evolved into complex devices that can includemillions of transistors, capacitors, and resistors on a single chip. Theevolution of chip design continually requires faster circuitry andgreater circuit density that demand increasingly precise fabricationprocesses. One fabrication process frequently used is ion implantation.

Ion implantation is particularly important in forming transistorstructures on semiconductor substrates and may be repeated many timesduring chip fabrication. During ion implantation, a semiconductorsubstrate, typically comprising a silicon material and/or a siliconcontaining film, is bombarded by a beam of electrically charged ions,commonly called dopants. Ion implantation changes the properties of thematerial in which the dopants are implanted in order to achieve aparticular level of electrical performance. Dopant concentration may bedetermined by controlling the number of ions in a beam of energyprojected on the substrate and the number of times the substrate passesthrough the beam. The dopants are accelerated to an energy level thatwill enable the dopants to penetrate the silicon material or implantinto the film at a desired depth. The energy level of the beam typicallydetermines the depth at which the dopants are placed.

During ion implantation, the implanted film may develop a high level ofinternal stress. In order to relieve the stress and further control theresulting properties of the implanted film, the film is typicallysubjected to a thermal process, such as annealing. Post-ion implantationannealing is typically performed in a rapid thermal processing (RTP)chamber that subjects the substrate to a very brief, yet highlycontrolled thermal cycle that can heat the substrate from roomtemperature to approximately 450° C. to about 1400° C. RTP typicallyminimizes or relieves the stress induced during implantation and can beused to further modify film properties, such as changing the electricalcharacteristics of the film by controlling dopant diffusion.

The RTP heating regime generally includes heating from a radiant heatsource, such as lamps and/or resistive heating elements. In aconventional RTP system, the substrate is heated to a desiredtemperature, and then the radiant heat source is turned off, whichcauses the substrate to cool. In some systems, a gas may be flowed ontothe substrate to enhance cooling. However, as processing parameterscontinue to evolve, temperature ramp up and heating uniformity duringRTP requires closer monitoring and control. While conventional RTPchambers rely on the radiant heat source to rapidly heat the substrateto a desired temperature, the challenges arise when the substraterequires cooling to improve heating uniformity, and/or when thesubstrate needs to be rapidly cooled. For example, if a significanttemperature gradient exists across the substrate, the substrate mayplastically deform or warp, which may be detrimental to subsequentprocesses performed on the substrate. Further, the faster cooling and/orenhanced temperature control of the substrate may result in higherthroughput and enhanced dopant uniformity.

Therefore, what is needed is an apparatus and method for rapid heatingand cooling of a semiconductor substrate, with enhanced control of heatuniformity.

SUMMARY OF THE INVENTION

The present invention generally describes a method for thermallytreating a substrate. In one embodiment, a method for thermally treatinga substrate is provided. The method includes transferring a substrate ata first temperature to a substrate support in a chamber, the chamberhaving a heating source and a cooling source disposed in opposingportions of the chamber, heating the substrate to a second temperatureduring a first time period while the substrate is disposed on thesubstrate support, heating the substrate to a third temperature during asecond time period while the substrate is disposed on the substratesupport, and cooling the substrate in the chamber to a fourthtemperature that is substantially equal to the second temperature duringthe second time period.

In another embodiment, a method for thermally treating a substrate isprovided. The method includes transferring a substrate at a firsttemperature to a substrate support in a chamber, the chamber having aheating source and a cooling source disposed in opposing portions of thechamber, heating the substrate to a second temperature during a firsttime period while the substrate is disposed on the substrate support,moving the substrate support between the heating source and the coolingsource, heating the substrate to a third temperature during a secondtime period while the substrate is disposed on the substrate support,and cooling the substrate in the chamber to a fourth temperature that issubstantially equal to the second temperature during the second timeperiod.

In another embodiment, a method for thermally treating a substrate isprovided. The method includes transferring a substrate at a firsttemperature that is at or near room temperature to a substrate supportin a chamber, the substrate support being adjacent a heating sourcedisposed in a first end of the chamber, heating the substrate to asecond temperature during a first time period while the substrate isdisposed on the substrate support, heating the substrate to a thirdtemperature during a second time period while the substrate is disposedon the substrate support, and moving the substrate while the substrateis disposed on the substrate support toward a cooling source disposed inan opposing second end of the chamber to cool the substrate to a fourthtemperature that is substantially equal to the second temperature duringthe second time period.

BRIEF DESCRIPTION OF THE DRAWINGS

So that the manner in which the above recited features of the presentinvention can be understood in detail, a more particular description ofthe invention, briefly summarized above, may be had by reference toembodiments, some of which are illustrated in the appended drawings. Itis to be noted, however, that the appended drawings illustrate onlytypical embodiments of this invention and are therefore not to beconsidered limiting of its scope, for the invention may admit to otherequally effective embodiments.

FIG. 1 is a simplified isometric view of one embodiment of a rapidthermal processing (RTP) chamber.

FIG. 2 is an isometric view of one embodiment of a substrate support.

FIG. 3 is a schematic side view of another embodiment of a RTP chamber.

FIG. 4 is a partial schematic side view of another embodiment of a RTPchamber.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. It is contemplated that elements disclosed in oneembodiment may be beneficially utilized on other embodiments withoutspecific recitation.

DETAILED DESCRIPTION

FIG. 1 is a simplified isometric view of one embodiment of a rapidthermal processing chamber 100. Examples of rapid thermal processingchambers that may be adapted to benefit from the invention are Quantum Xplus and CENTURA® thermal processing systems, both available fromApplied Materials, Inc., located in Santa Clara, Calif. Although theapparatus is described as utilized within a rapid thermal processingchamber, embodiments described herein may be utilized in otherprocessing systems and devices where at least two temperature zoneswithin one processing region is desired, such as substrate supportplatforms adapted for robot handoffs, orientation devices, depositionchambers, etch chambers, electrochemical processing apparatuses andchemical mechanical polishing devices, among others, particularly wherethe minimization of particulate generation is desired.

The processing chamber 100 includes a contactless or magneticallylevitated substrate support 104, a chamber body 102, having walls 108, abottom 110, and a top 112 defining an interior volume 120. The walls 108typically include at least one substrate access port 148 to facilitateentry and egress of a substrate 140 (a portion of which is shown in FIG.1). The access port may be coupled to a transfer chamber (not shown) ora load lock chamber (not shown) and may be selectively sealed with avalve, such as a slit valve (not shown). In one embodiment, thesubstrate support 104 is annular and the chamber 100 includes a radiantheat source 106 disposed in an inside diameter of the substrate support104. Examples of a RTP chamber that may be modified and a substratesupport that may be used is described in U.S. Pat. No. 6,800,833, filedMar. 29, 2002 and issued on October 5, 2004, U.S. patent applicationSer. No. 10/788,979, filed Feb. 27, 2004 and published as United StatesPatent Publication No. 2005/0191044 on Sep. 1, 2005, both of which areincorporated by reference in their entireties.

The substrate support 104 is adapted to magnetically levitate and rotatewithin the interior volume 120. The substrate support 104 is capable ofrotating while raising and lowering vertically during processing, andmay also be raised or lowered without rotation before, during, or afterprocessing. This magnetic levitation and/or magnetic rotation preventsor minimizes particle generation due to the absence or reduction ofmoving parts typically required to raise/lower and/or rotate thesubstrate support.

The chamber 100 also includes a window 114 made from a materialtransparent to heat and light of various wavelengths, which may includelight in the infra-red (IR) spectrum, through which photons from theradiant heat source 106 may heat the substrate 140. In one embodiment,the window 114 is made of a quartz material, although other materialsthat are transparent to light may be used, such as sapphire. The window114 may also include a plurality of lift pins 144 coupled to an uppersurface of the window 114, which are adapted to selectively contact andsupport the substrate 140, to facilitate transfer of the substrate intoand out of the chamber 100. Each of the plurality of lift pins 144 areconfigured to minimize absorption of energy from the radiant heat source106 and may be made from the same material used for the window 114, suchas a quartz material. The plurality of lift pins 144 may be positionedand radially spaced from each other to facilitate passage of an endeffector coupled to a transfer robot (not shown). Alternatively, the endeffector and/or robot may be capable of horizontal and vertical movementto facilitate transfer of the substrate 140.

In one embodiment, the radiant heat source 106 includes a lamp assemblyformed from a housing which includes a plurality of honeycomb tubes 160in a coolant assembly 360 (shown in FIG. 3) coupled to a coolant source183. The coolant source 183 may be one or a combination of water,ethylene glycol, nitrogen (N₂), and helium (He). The housing may be madeof a copper material or other suitable material having suitable coolantchannels formed therein for flow of the coolant from the coolant source183. Each tube 160 may contain a reflector and a high-intensity lampassembly or an IR emitter from which is formed a honeycomb-like pipearrangement. This close-packed hexagonal arrangement of pipes providesradiant energy sources with high-power density and good spatialresolution. In one embodiment, the radiant heat source 106 providessufficient radiant energy to thermally process the substrate, forexample, annealing a silicon layer disposed on the substrate 140. Theradiant heat source 106 may further comprise annular zones, wherein thevoltage supplied to the plurality of tubes 160 by the controller 124 mayvaried to enhance the radial distribution of energy from the tubes 160.Dynamic control of the heating of the substrate 140 may be affected bythe one or more temperature sensors 117 (described in more detail below)adapted to measure the temperature across the substrate 140.

A stator assembly 118 circumscribes the walls 108 of the chamber body102 and is coupled to one or more actuator assemblies 122 that controlthe elevation of the stator assembly 118 along the exterior of thechamber body 102. In one embodiment (not shown), the chamber 100includes three actuator assemblies 122 disposed radially about thechamber body, for example, at about 120° angles about the chamber body102. The stator assembly 118 is magnetically coupled to the substratesupport 104 disposed within the interior volume 120 of the chamber body102. The substrate support 104 may comprise or include a magneticportion to function as a rotor, thus creating a magnetic bearingassembly to lift and/or rotate the substrate support 104. In oneembodiment, at least a portion of the substrate support 104 is partiallysurrounded by a trough 412 (shown in FIG. 4) that is coupled to a fluidsource 186, which may include water, ethylene glycol, nitrogen (N₂),helium (He), or combinations thereof, adapted as a heat exchange mediumfor the substrate support. The stator assembly 118 may also include ahousing 190 to enclose various parts and components of the statorassembly 118. In one embodiment, the stator assembly 118 includes adrive coil assembly 168 stacked on a suspension coil assembly 170. Thedrive coil assembly 168 is adapted to rotate and/or raise/lower thesubstrate support 104 while the suspension coil assembly 170 may beadapted to passively center the substrate support 104 within theprocessing chamber 100. Alternatively, the rotational and centeringfunctions may be performed by a stator having a single coil assembly.

An atmosphere control system 164 is also coupled to the interior volume120 of the chamber body 102. The atmosphere control system 164 generallyincludes throttle valves and vacuum pumps for controlling chamberpressure. The atmosphere control system 164 may additionally include gassources for providing process or other gases to the interior volume 120.The atmosphere control system 164 may also be adapted to deliver processgases for thermal deposition processes.

The chamber 100 also includes a controller 124, which generally includesa central processing unit (CPU) 130, support circuits 128 and memory126. The CPU 130 may be one of any form of computer processor that canbe used in an industrial setting for controlling various actions andsub-processors. The memory 126, or computer-readable medium, may be oneor more of readily available memory such as random access memory (RAM),read only memory (ROM), floppy disk, hard disk, or any other form ofdigital storage, local or remote, and is typically coupled to the CPU130. The support circuits 128 are coupled to the CPU 130 for supportingthe controller 124 in a conventional manner. These circuits includecache, power supplies, clock circuits, input/output circuitry,subsystems, and the like.

In one embodiment, each of the actuator assemblies 122 generallycomprise a precision lead screw 132 coupled between two flanges 134extending from the walls 108 of the chamber body 102. The lead screw 132has a nut 158 that axially travels along the lead screw 132 as the screwrotates. A coupling 136 is coupled between the stator assembly 118 andnut 158 so that as the lead screw 132 is rotated, the coupling 136 ismoved along the lead screw 132 to control the elevation of the statorassembly 118 at the interface with the coupling 136. Thus, as the leadscrew 132 of one of the actuator assemblies 122 is rotated to producerelative displacement between the nuts 158 of the other actuatorassemblies 122, the horizontal plane of the stator assembly 118 changesrelative to a central axis of the chamber body 102.

In one embodiment, a motor 138, such as a stepper or servo motor, iscoupled to the lead screw 132 to provide controllable rotation inresponse to a signal by the controller 124. Alternatively, other typesof actuator assemblies 122 may be utilized to control the linearposition of the stator assembly 118, such as pneumatic cylinders,hydraulic cylinders, ball screws, solenoids, linear actuators and camfollowers, among others.

The chamber 100 also includes one or more sensors 116, which aregenerally adapted to detect the elevation of the substrate support 104(or substrate 140) within the interior volume 120 of the chamber body102. The sensors 116 may be coupled to the chamber body 102 and/or otherportions of the processing chamber 100 and are adapted to provide anoutput indicative of the distance between the substrate support 104 andthe top 112 and/or bottom 110 of the chamber body 102, and may alsodetect misalignment of the substrate support 104 and/or substrate 140.

The one or more sensors 116 are coupled to the controller 124 thatreceives the output metric from the sensors 116 and provides a signal orsignals to the one or more actuator assemblies 122 to raise or lower atleast a portion of the substrate support 104. The controller 124 mayutilize a positional metric obtained from the sensors 116 to adjust theelevation of the stator assembly 118 at each actuator assembly 122 sothat both the elevation and the planarity of the substrate support 104and substrate 140 seated thereon may be adjusted relative to and acentral axis of the RTP chamber 100 and/or the radiant heat source 106.For example, the controller 124 may provide signals to raise thesubstrate support by action of one actuator assembly 122 to correctaxial misalignment of the substrate support 104, or the controller mayprovide a signal to all actuator assemblies 122 to facilitatesimultaneous vertical movement of the substrate support 104.

The one or more sensors 116 may be ultrasonic, laser, inductive,capacitive, or other type of sensor capable of detecting the proximityof the substrate support 104 within the chamber body 102. The sensors116, may be coupled to the chamber body 102 proximate the top 112 orcoupled to the walls 108, although other locations within and around thechamber body 102 may be suitable, such as coupled to the stator assembly118 outside of the chamber 100. In one embodiment, one or more sensors116 may be coupled to the stator assembly 118 and are adapted to sensethe elevation and/or position of the substrate support 104 (or substrate140) through the walls 108. In this embodiment, the walls 108 mayinclude a thinner cross-section to facilitate positional sensing throughthe walls 108.

The chamber 100 also includes one or more temperature sensors 117, whichmay be adapted to sense temperature of the substrate 140 before, during,and after processing. In the embodiment depicted in FIG. 1, thetemperature sensors 117 are disposed through the top 112, although otherlocations within and around the chamber body 102 may be used. Thetemperature sensors 117 may be optical pyrometers, as an example,pyrometers having fiber optic probes. The sensors 117 may be adapted tocouple to the top 112 in a configuration to sense the entire diameter ofthe substrate, or a portion of the substrate. The sensors 117 maycomprise a pattern defining a sensing area substantially equal to thediameter of the substrate, or a sensing area substantially equal to theradius of the substrate. For example, a plurality of sensors 117 may becoupled to the top 112 in a radial or linear configuration to enable asensing area across the radius or diameter of the substrate. In oneembodiment (not shown), a plurality of sensors 117 may be disposed in aline extending radially from about the center of the top 112 to aperipheral portion of the top 112. In this manner, the radius of thesubstrate may be monitored by the sensors 117, which will enable sensingof the diameter of the substrate during rotation.

The RTP chamber 100 also includes a cooling block 180 adjacent to,coupled to, or formed in the top 112. Generally, the cooling block 180is spaced apart and opposing the radiant heat source 106. The coolingblock 180 comprises one or more coolant channels 184 coupled to an inlet181A and an outlet 181B. The cooling block 180 may be made of a processresistant material, such as stainless steel, aluminum, a polymer, or aceramic material. The coolant channels 184 may comprise a spiralpattern, a rectangular pattern, a circular pattern, or combinationsthereof and the channels 184 may be formed integrally within the coolingblock 180, for example by casting the cooling block 180 and/orfabricating the cooling block 180 from two or more pieces and joiningthe pieces. Additionally or alternatively, the coolant channels 184 maybe drilled into the cooling block 180.

As described herein, the chamber 100 is adapted to receive a substratein a “face-up” orientation, wherein the deposit receiving side or faceof the substrate is oriented toward the cooling block 180 and the“backside” of the substrate is facing the radiant heat source 106. The“face-up” orientation may allow the energy from the radiant heat source106 to be absorbed more rapidly by the substrate 140 as the backside ofthe substrate is typically less reflective than the face of thesubstrate.

Although the cooling block 180 and radiant heat source 106 is describedas being positioned in an upper and lower portion of the interior volume120, respectively, the position of the cooling block 180 and the radiantheat source 106 may be reversed. For example, the cooling block 180 maybe sized and configured to be positioned within the inside diameter ofthe substrate support 104, and the radiant heat source 106 may becoupled to the top 112. In this arrangement, the quartz window 114 maybe disposed between the radiant heat source 106 and the substratesupport 104, such as adjacent the radiant heat source 106 in the upperportion of the chamber 100. Although the substrate 140 may absorb heatmore readily when the backside is facing the radiant heat source 106,the substrate 140 could be oriented in a face-up orientation or a facedown orientation in either configuration.

The inlet 181A and outlet 181B may be coupled to a coolant source 182 byvalves and suitable plumbing and the coolant source 182 is incommunication with the controller 124 to facilitate control of pressureand/or flow of a fluid disposed therein. The fluid may be water,ethylene glycol, nitrogen (N₂), helium (He), or other fluid used as aheat exchange medium.

FIG. 2 is an isometric view of one embodiment of a substrate support104. The substrate support 104 includes an annular body 220 having aninside diameter 209 sized to receive the radiant heat source and otherhardware (not shown in this view). The substrate support 104 is at leastpartially comprised of a magnetic ring section 208 and a support section212. The magnetic ring section 208 may be at least partially comprisedof a magnetic material, such as a ferrous containing material, tofacilitate magnetic coupling of the substrate support 104 to the statorassembly 118. The ferrous containing material includes low carbon steel,stainless steel, which may include a plating, such as a nickel plating.In one embodiment, the magnetic ring section 208 is comprised of aplurality of permanent magnets disposed in a polar array about a centralaxis. The magnetic ring section 208 may additionally include an outersurface having one or more channels 223 formed therein. In oneembodiment, the magnetic ring section 208 includes a shaped profile,such as an “E” shape or “C” shape having one or more channels 223 formedtherein.

The support section 212 is generally adapted to minimize energy loss,such as heat and/or light, from the radiant heat source 106, such that asubstantial portion of energy from the radiant heat source 106 iscontained within the region between the lower surface of the substrate140 and the upper end of the radiant heat source 106 (not shown in thisFigure). The support section 212 may be an annular extension 214extending from an upper surface of the magnetic ring section 208. Thesupport section 212 may also include a support ring 210 that, in oneembodiment, facilitates alignment and provides a seating surface 202 forthe substrate 140. In one embodiment, at least a portion of the supportring 210 is made from a material that is transparent to energy from theradiant heat source 106, such as a quartz material. In anotherembodiment, the support ring 210 comprises a silicon carbide materialthat may be sintered. The support ring 210 may further include an oxidecoating or layer, which may comprise nitrogen. An example of a supportring 210 that may be used is described in U.S. Pat. No. 6,888,104, filedFeb. 5, 2004, and issued on May 3, 2005, which is incorporated byreference in its entirety.

The support ring 210 generally includes an inner wall 222 and a supportlip 219 extending inwardly from the inner wall 222. The inner wall 222may be sized slightly larger than the substrate in a stepwise or slopedfashion and facilitates alignment and/or centering of the substrate 140when the substrate support 104 is raised. The substrate may then beseated on the support lip 219 and substrate centering is maintainedduring lifting and/or rotation of the substrate support 104. The supportring 210 may also include an outer wall that extends downward from theupper surface of the support ring 210 opposite the inner wall 222. Thearea between the outer wall and inner wall 222 forms a channel 224 thatfacilitates alignment of the support ring 210 on the annular extension214. The support section 212 may be coupled to the magnetic ring section208 by fastening, bonding, or gravitationally, and is adapted to supportthe substrate 140 during processing. In one embodiment, the support ring210 functions as an edge ring and may be gravitationally attached to theannular extension 214 for easy removal and replacement.

The support section 212 may be fabricated from a material that reducespotential scratching, chemical or physical contamination, and/or marringof the substrate, for example, materials such as silicon carbide,stainless steel, aluminum, ceramic, or a high temperature polymer may beused. Alternatively, the support section 212 may be fabricated as aunitary member from the material of the magnetic ring section 208. Atleast a portion of the support section 212 may be fabricated or coatedwith a reflective material, or made of or coated with a black materialto absorb heat similar to a black body, depending on process parameters.It is to be noted that a black material as used herein may include darkcolors, such as the color black, but is not limited to dark coloredmaterials or coatings. More generally, a black material, a black finish,or a black coating refers to the lack of reflectivity or the ability thematerial, finish, or coating to absorb energy, such as heat and/orlight, similar to a black body.

FIG. 3 is a schematic side view of another embodiment of a RTP chamber300 which includes a chamber body 102, having walls 108, a bottom 110,and a top 112, defining an interior volume 120 as in FIG. 1. The chamber300 also includes a contactless or magnetically levitated substratesupport 104 as in FIG. 1, but the stator and other components outsidethe chamber 100 are not shown for clarity. In this embodiment, thesubstrate support 104 is depicted in an exchange position, wherein theplurality of lift pins 144 is supporting the substrate 140 to facilitatetransfer of the substrate.

In this embodiment, a portion of the substrate support 104 and/or themagnetic ring section 208 may rest at or near an upper surface of thebottom 110 of the chamber body 102, and the window 114 is supported byone of the upper surface of the magnetic ring section 208 and/or asidewall 312 coupled to or otherwise supported by the upper surface ofthe bottom 110. The sidewall 312 may be sidewalls of a coolant assembly360 around a portion of the radiant heat source 106 disposed in theinside diameter of the substrate support 104, or the sidewalls 312 maybe support members coupled to the upper surface of the bottom 110 withinthe inside diameter of the substrate support 104 and outside of thecoolant assembly 360. An adaptor plate 316 may also be coupled to thechamber bottom 110 to facilitate connection of wires and other supportdevices for the radiant heat source 106 and/or the coolant assembly 360.

The support section 212 may be an annular extension 214 extending froman upper surface of the substrate support 104 or the magnetic ringsection 208. The support section 212 may also include a support ring 210that provides alignment and a seating surface for the substrate 140. Thesupport ring 210 includes an inner wall 222 and a support lip 219extending inwardly from the inner wall 222. The inner wall 222 may besized slightly larger than the substrate and facilitates alignmentand/or centering of the substrate 140 when the substrate support 104 israised. The substrate 140 may then be seated on the support lip 219 andsubstrate centering is maintained during lifting and/or rotation of thesubstrate support 104.

In one embodiment, the cooling block 180 includes a plurality of coolantchannels 348A-348C for circulating a cooling fluid as described above.The coolant channels may be separate channels or discrete flow paths, orthe coolant channels may comprise a plurality of closed flow pathscoupled to the coolant source 182. In one embodiment, the cooling block180 comprises multiple cooling zones, such as an outer zone definedgenerally by the coolant channel 348A, an inner zone defined generallyby coolant channel 348C, and an intermediate zone generally defined bycoolant channel 348B. The outer zone may correspond to the periphery ofthe substrate 140 while the inner and intermediate zones may correspondto a central portion of the substrate 140. The coolant temperatureand/or coolant flow may be controlled in these zones to provide, forexample, more cooling on the periphery of the substrate 140 relative tothe center of the substrate. In this manner, the cooling block 180 mayprovide enhanced temperature control of the substrate 140 by providingmore or less cooling in regions of the substrate where cooling is neededor desired.

The cooling block 180 may be formed from a material such as aluminum,stainless steel, nickel, a ceramic, or a process resistant polymer. Thecooling block 180 may comprise a reflective material, or include areflective coating configured to reflect heat onto the substratesurface. Alternatively, the cooling block 180 may comprise a blackmaterial (such as a black material configured to absorb energysubstantially similar to a black body) or otherwise coated or finishedwith a black material or surface that is configured to absorb heat fromthe substrate and/or the interior volume 120. The cooling block 180 mayalso include a face or outer surface 332 that may be roughened orpolished to promote reflectivity or absorption of radiant energy in theform of heat and/or light. The outer surface 332 may also include acoating or finish to promote reflectivity or absorption, depending onthe process parameters. In one embodiment, the cooling block 180 may bea black material or a material resembling a black material, or otherwisecoated or finished with a black material or resembling a black material,to have an emissivity or emittance near 1, such as an emissivity betweenabout 0.70 to about 0.95.

As shown in FIG. 3, the interior volume 120 comprises a temperaturetransition zone 305, or processing zone depicted as distance D₃, whichincludes a heating region 306A and a cooling region 306B that thesubstrate 140 may be exposed to during processing. The regions 306A,306B enable rapid heating and rapid cooling of the substrate 140 duringprocessing in the interior volume 120. As an example, heating region306A may enable a temperature on the face of the substrate 140 that isbetween about 450° C. to about 1400° C. during processing, and thecooling region 306B may cool the face of the substrate 140 to about roomtemperature or lower during processing, depending on process parameters.

For example, the substrate may be transferred to the RTP chamber at roomtemperature, or some temperature above room temperature provided by aheating means in a load lock chamber, or other peripheral chamber ortransfer device. The temperature of the substrate before, during, orafter transfer of the substrate to the RTP chamber may be referred to asthe first or introduction temperature, from which the RTP process may beinitiated. In one embodiment, the introduction temperature may bebetween about room temperature, to about 600° C. Once the substrate isintroduced to the chamber, the substrate may be rapidly heated, takingthe temperature of the substrate from the introduced temperature to asecond temperature of between about 800° C. to about 1200° C., such asabout 900° C. to about 1150° C. In one embodiment, power to the radiantheat source is varied and monitored, using feedback from the sensors117, to enable a second temperature of about 900° C. to about 1150° C.across the substrate in a heating step or first heating period.

In one embodiment, the first heating period is configured to raise thetemperature of the substrate from the introduction temperature to about900° C. to about 1150° C. across the substrate in about 2 minutes orless, such as between about 50 seconds and about 90 seconds, forexample, between about 55 seconds and about 75 seconds. After thesubstrate has reached the second temperature in the heating period, aspike or transition period may begin, which includes a second heatingperiod. The second heating period may include heating the substrate to athird temperature of about 25° C. to about 100° C. higher than thesecond temperature. The transition period also includes lowering thetemperature of the substrate to a fourth temperature, which is about 25°C. to about 100° C. lower than the third temperature. In one embodiment,the third temperature and the fourth temperature are within about 5° C.to about 20° C. of each other, and in another embodiment, the thirdtemperature and the fourth temperature are substantially equal. Thetransition period may include a third period of about 3 seconds or less,such as about 0.1 seconds to about 2 seconds, for example, between about0.3 seconds to about 1.8 seconds.

After the transition period, the substrate may be placed adjacent thecooling block 180 and rapidly cooled by one or both of the cooling block180 and coolant source 315 (described in more detail below). Thesubstrate may be cooled to a temperature substantially equal to thefirst or introduction temperature in a fourth period that may be lessthan 10 seconds, such as about 2 seconds to about 6 seconds. Thesubstrate may be cooled rapidly to a desired temperature, including atemperature at or near room temperature, or be cooled to a temperatureabove room temperature that enables transfer, which may enhancethroughput.

The rapid heating and cooling of the substrate, as described above,provides many benefits. The temperature of the substrate is constantlymonitored by feed back from the sensors 117, and enhanced control of thesubstrate temperature may be facilitated by moving the substraterelative the cooling block 180 and/or the radiant heat source 106.Dopant diffusion control may be enhanced by the rapid and controlledheating and cooling of the substrate, and device performance may beimproved. Additionally, the lessened heating and cooling times mayincrease throughput.

To enable the rapid heating and cooling of the substrate, the substratemay travel in the temperature transition zone 305. The travel of thesubstrate 140 in the interior volume 120 and the regions 306A, 306Bfacilitate a sharper transition and/or a lower residence time betweenheating and cooling of the substrate. In one example, once the substrate140 is placed in a processing position, the heating region 306A of thetemperature transition zone 305 may include a travel distance D₁ for thesubstrate 140 (or substrate support 104), for example, between about 0.5inches to about 1.5 inches. The cooling region 306B of the temperaturetransition zone may include a travel distance D₂ for the substrate 140(or substrate support 104) between about 0.5 inches to about 1.5 inches.In one embodiment, the total travel of the substrate 140 (or substratesupport 104) within the interior volume, such as between the radiantheat source 106 and the cooling block 180, is between about 0.75 inchesto about 3.25 inches, for example, between about 1.0 inches and about2.75 inches, such as about 2 inches. In one embodiment, the distance D₁comprises about one half of the distance D₃, and the distance D₂comprises about one half of the distance D₃. The substrate support 104may be configured to raise the substrate to a position that is in closeproximity to the substrate 140, depending on the flatness of thesubstrate and other physical properties of the substrate, and themechanical characteristics of the substrate support. Assuming thesubstrate has a suitable flatness, and the substrate support 104 andsubstrate disposed thereon is substantially parallel to the coolingblock 180, the substrate may be raised to be within about 0.005 inchesto about 0.025 inches from the lower surface of the cooling block 180.Bringing the substrate in close proximity to the cooling block enablesrapid heat transfer and enhanced cooling of the substrate.

In one embodiment, the chamber 300 includes a gas port 310 coupled to acoolant source 315. The gas port 310 may be a manifold or a plurality ofopenings that are formed or otherwise coupled to the upper portion ofthe chamber wall 108, and may be formed as, or adapted to couple to, anozzle that enables laminar flow through the cooling region 306B, forexample adjacent to the outer surface 332 of the cooling block 180. Toenable a more enhanced flow path, the chamber also includes an exit port320 formed in the chamber wall 108, typically opposing the gas port 310.The exit port 320 may be coupled to a vacuum source configured to assistthe atmosphere control system 164 (FIG. 1) and remove excess gasprovided by the gas port 310. The coolant source 315 includes a coolingfluid, such as helium (He), nitrogen (N₂), or other suitable coolingfluid, and is directed or configured to flow within the cooling region306B. The cooling fluid from the gas port 310 enables more rapid coolingof the substrate 140 when the substrate is positioned in the coolingregion 306B.

As described in reference to FIG. 1, the radiant heat source 106 iscoupled to a coolant assembly 360 that is adapted to maintain a suitabletemperature and/or cool the honeycomb tubes 160 of the radiant heatsource 106. The coolant assembly 360 includes sidewalls 312 and a bottom314 that is adapted to contain a fluid. The bottom 314 includes ports323 and 324 that are configured to supply and remove coolant fluid fromthe coolant source 183, which may be water, ethylene glycol, or othersuitable cooling fluid. The coolant assembly 360 may also include aplurality of fluid channels formed therein (described in reference toFIG. 4) for enhanced thermal transfer from the cooling fluid and theradiant heat source 106.

FIG. 4 is partial side view of another embodiment of a RTP chamber in aprocessing position and details of the coolant assembly 360 will bedescribed. The coolant assembly 360 includes a bottom 322 and sidewalls312 as shown in other Figures, and also includes a body 427, whichcomprises a plurality of partitions 426 separating the plurality ofhoneycomb tubes 160. The body may also comprise a plate 423 opposing thebottom 322, to form a void 446 therebetween, which is configured tocontain the coolant from a first coolant source 485A and separate thevoid 446 from the plurality of honeycomb tubes 160. The void 446 is incommunication with the coolant source 485A by a port 324 coupled to thebottom 322 and the port 324 is in communication with a plenum 445 thatis in fluid communication with the void 446 by a plenum port 415. Theplate 423 may include a plurality of channels or grooves 428 formedtherein to increase the surface area available to the cooling fluid,thus enhancing heat dissipation from the radiant heat source 106.

In operation, a cooling fluid is supplied from the first source 485A tothe void 446 by the port 323, and the coolant at least partially fillsthe void 446. The coolant may be continually flowed into the void todissipate heat and exits the void through the plenum port 415 to theplenum 445. The coolant may be removed from the plenum 445 by the port324 and returned to the first source 485A. The coolant may bereplenished and/or cooled before cycling through the void 446. In thismanner, the temperature of the radiant heat source 106 is controlled.

The coolant assembly 360 may also includes a plurality of fluid channels425 formed in at least a portion of the plurality of partitions 426. Thefluid channels 425 are configured to flow a cooling fluid, such aswater, ethylene glycol, nitrogen (N₂), helium (He), or other fluid usedas a heat exchange medium, from a second coolant source 485B. The fluidchannels 425 are coupled to the second coolant source 485B by at leastone inlet and outlet (not shown). The flowing of coolant from the firstand second sources 485A, 485B facilitates enhanced temperature controlof the radiant heat source 106.

The chamber 100 also includes a magnetically levitated or contactlesssubstrate support 104 having a support ring 210 and a support section212 configured as an annular extension coupled to an annular body 220disposed in a channel or trough 412. The trough 412 is coupled to afluid source 186 through a port 420 for supplying a coolant to thetrough 412, thus dissipating heat that may be transferred from theradiant heat source 106 and/or heat created by rotation of the annularbody 220 during processing. The fluid source 186 may include coolingfluids, such as water, ethylene glycol, nitrogen (N₂), helium (He), orother fluid used as a heat exchange medium. A gap 418 may also be formedbetween the sidewall 312 of the coolant assembly 360 and a sidewall ofthe trough 412 to facilitate insulation between the annular body 220 ofthe substrate support 104 and the radiant heat source 106.

While the foregoing is directed to embodiments of the present invention,other and further embodiments of the invention may be devised withoutdeparting from the basic scope thereof, and the scope thereof isdetermined by the claims that follow.

1. A method for thermally treating a substrate, comprising: transferringa substrate at a first temperature to a substrate support in a chamber,the chamber having a heating source and a cooling source disposed inopposing portions of the chamber; heating the substrate to a secondtemperature during a first time period while the substrate is disposedon the substrate support; heating the substrate to a third temperatureduring a second time period while the substrate is disposed on thesubstrate support; and cooling the substrate in the chamber to a fourthtemperature that is substantially equal to the second temperature duringthe second time period.
 2. The method of claim 1, wherein the secondtime period is about 2 seconds or less.
 3. The method of claim 1,further comprising: moving the substrate support between the heatingsource and the cooling source.
 4. The method of claim 1, wherein thefirst temperature is a temperature at or near room temperature.
 5. Themethod of claim 4, further comprising: transferring the substrate out ofthe chamber after the substrate is cooled to a temperature that isgreater than room temperature.
 6. The method of claim 1, wherein thethird temperature is about 25 degrees Celsius to about 100 degreesCelsius greater than the second temperature.
 7. The method of claim 1,wherein the cooling source comprises a gas port configured to flow acooling gas across the upper portion of the chamber.
 8. The method ofclaim 1, wherein the cooling source comprises a cooling plate disposedin the chamber.
 9. The method of claim 8, wherein the cooling platecomprises at least one coolant channel.
 10. The method of claim 8,wherein the cooling plate comprises a material having an emissivity ofabout 0.70 to about 0.95.
 11. A method for thermally treating asubstrate, comprising: transferring a substrate at a first temperatureto a substrate support in a chamber, the chamber having a heating sourceand a cooling source disposed in opposing portions of the chamber;heating the substrate to a second temperature during a first time periodwhile the substrate is disposed on the substrate support; moving thesubstrate support between the heating source and the cooling source;heating the substrate to a third temperature during a second time periodwhile the substrate is disposed on the substrate support; and coolingthe substrate in the chamber to a fourth temperature that issubstantially equal to the second temperature during the second timeperiod.
 12. The method of claim 11, wherein the first temperature is atemperature at or near room temperature.
 13. The method of claim 11,further comprising: transferring the substrate out of the chamber afterthe substrate is cooled to a temperature that is less than the secondtemperature.
 14. The method of claim 13, further comprising:transferring the substrate out of the chamber after the substrate iscooled to a temperature that is greater than room temperature.
 15. Themethod of claim 11, wherein the third temperature is about 25 degreesCelsius to about 100 degrees Celsius greater than the secondtemperature.
 16. A method for thermally treating a substrate,comprising: transferring a substrate at a first temperature that is ator near room temperature to a substrate support in a chamber, thesubstrate support being adjacent a heating source disposed in a firstend of the chamber; heating the substrate to a second temperature duringa first time period while the substrate is disposed on the substratesupport; heating the substrate to a third temperature during a secondtime period while the substrate is disposed on the substrate support;and moving the substrate while the substrate is disposed on thesubstrate support toward a cooling source disposed in an opposing secondend of the chamber to cool the substrate to a fourth temperature that issubstantially equal to the second temperature during the second timeperiod.
 17. The method of claim 16, wherein the cooling source comprisesa gas port configured to flow a cooling gas across the upper portion ofthe chamber.
 18. The method of claim 16, wherein the cooling sourcecomprises a cooling plate disposed in the chamber.
 19. The method ofclaim 18, wherein the cooling plate comprises at least one coolantchannel.
 20. The method of claim 18, wherein the cooling plate comprisesa material having an emissivity of about 0.70 to about 0.95.